Display panels, such as liquid crystal displays and organic light-emitting diode displays, are widely used in electronic devices. The display panel has been designed with a larger size to meet various requirements. In general, a large-sized display panel is “virtually” divided into multiple sub-regions such that the sub-regions may be driven by multiple driving circuits, respectively.
FIG. 1 schematically illustrates a block diagram of a driving circuit for a display panel that is divided into 2×2 sub-regions. In this case, four driving circuit boards are employed, each of which has an individual gamma voltage generation circuit. Inconsistency between gamma voltages generated by different gamma voltage generation circuits may lead to luminance differences among the four sub-regions at the same grayscale, which in turn causes non-uniformity of grayscales (known as “mura”).